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R. G. McARTHUR.

DEVICE FOR OPERATING THROTTLE VALVES. No, 379,318. Patented Mar. 13, 1888.

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UNITED STATES PATENT Fries.

ROBERT CAMPBELL MCARTHUR, OF HAMILTON, ONTARIO, CANADA, AS- SIGNOR OF ONE-HALF TO WILLIAM D. FITCH, OF SAME PLACE.

DEVICE FOR OPERATING THROTTLE-VALVES.

SPECIFICATION forming part of Letters Patent No. 379,318, dated March 13, 1888.

(No model.)

To (tZl whom it may concern.-

Be it known that I, ROBERT CAMPBELL Ho- ARTHUR, of Hamilton, in the Provinceof Ontario, and Dominion of Canada, have invented a new and Improved Device for Operating Throttle-Valves and Reversing-Gear for Locomotives and Engines, of which the following is a full, clear, and exact descrip tion.

The object of my invention is to provide anew and improved device for locking the valvelever and its connecting-rod in any desired position.

The invention consists of a lever pivotally 1 connected with the valve-rod to be operated,

of cams or clutches pivoted on said lever and operating on the segmental arm held on said lever, and of means for throwing said cams in or out of contact with said segmental arm.

The invention also consists in the construction and arrangement of certain parts and details and combinations of the same, as will be ,fully described hereinafter, and then pointed out in the claims.

2 5 Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure l is a plan view of my improvement.

0 Fig. 2 is a sectional side elevation of the same on the line :v a; of Fig. 1. Fig. 3 is a bottom view of part of the lever, and Fig. 4 is a sectional plan view of my improvement on the line 9 y of Fig. 2.

The lever A is pivotally connected at one end with the link B, pivoted to the apparatus or boiler C, to which my improvement is applied. The rod D, which operates the throttle-valve or the reversing mechanism of the 0 locomotive or engine, is pivoted at E to the said lever A, which latter is provided with a bearing, F, supporting a segmental arm, G,

pivoted on a link, H, pivotally connected with the boiler or apparatus 0.

The cams or friction-clutches I I are pivoted to the lever A, and their eccentric lower ends, 1, operate on the periphery of the segmental arm G. The upper ends, 1*, of the cams I I rest against the edges of a wedge, J, and said ends I are provided with projecting pins 1,

engaging inclined slots K, formed in a plate,

K, secured by the pins J J to the wedge J. The pins J J pass through a slot, A, in the lever A and support, at the under side of the' lever A, a plate, L, on which is fastened one end of a spring, N, secured by its other end to the lever A, as is plainly shown in Figs. 2 and 3. The wedge J and the plates K and L are thus held on the lever A and are guided vertically by the pins J in the slot A of the lever A.

On one of the pins J is pivoted a link, 0, pivotally connected with an L-shaped lever, P, fulcrumed on the lever A. The spring N has a tendency to draw the wedge J downward, so that the latter presses the upper ends of the cams I I apart.

The operation is as follows: The device shown in Fig. l is in alocked central position in which the rod D is in a half-way position, and the lever A is held locked with the rod D on account of the wedge J pressing the ends I of the cams I apart by the action of the spring N, so that the lower eccentric ends, I, of said cams I I press tightly against the periphery of the arm G, whereby the rod D and the lever A cannot be moved in either direction. If the operator now desires to close the valve entirely or to open the same still farther, he presses the L-shaped lever P in- So wardtoward the handle ofthelever A, whereby the wedge J slides outward in the direction of the arrow a,carrying with it the plates L and K. The inclined slots K in the plate K thus cause an inward movement of the upper ends 8 of the cams I I, so that the lower eccentric ends, I, of the cams I are disengaged from the periphery of the segment G, and the operator is now enabled to move the lever A inward or outward on its fulcrum on the link B, c whereby the rod D is moved correspondingly and the valve can be either closed entirely or opened to its fullest extent. The outward movement of the plate L, as above described, increases the tension of the spring N, and as soon as the desired position of the rod D is reached, the operator releases his pressure on the lever P, so that the spring N causes the plates L and K and the wedge J to slide inward in the inverse direction of the arrow a, r00

whereby the outer ends, P, of the cams I are spread apart and the eccentric inner ends, I, of the said cams are moved tightlyin contact with the periphery of the segment G, thereby locking the lever A to the said segment G,and thus holding the rod D in any desired position.

It will be seen that the inclined slots K,engaging the pins 1" of the cams I, cause the latter to swing according to the movement of the plate K. It will also be seen that the rod D can be moved to any desired position by the lever A and both locked together, as above described.

Having thus fully described my invention, I claim as new and desire to secure by Letters Patent 1. The combination, with a valve-rod, of a lever pivotally connected with said valve-rod, a segment extending across and guided on said lever, and cams or clutches pivoted on said lever and held in contact with said segment, substantially as shown and described.

2. The combination, with the valve-rod and a segment, of a lever pivotally connected with said valve rod and guiding said segment,cams" or clutches pivotedon said lever and held in contact with said segment, and a lever for moving said cams out of contact with said segment, substantially as shown and described.

3. The combination,with the valve-rod and a segment, and a lever pivotally connected with said valve-rod and guiding said segment, of cams pivoted on said lever and held in contact with said segment, a plate having inclined slots engaging said cams, and a lever for moving said slotted plate, substantially as shown and described.

4. The combinatiomwith a valve-rod and a segment, and a lever pivotally connected with said valve-rod and guiding said segment, of 40 pivoted on said lever and adapted to engage u said segment, pins projecting from said cams, a plate guided on said lever and provided with inclined slots engaging said pins, aspring exerting an inward pressure against said top plate, and a second lever fulcrumed on said first-named lever and pivotally connected with said slotted plate, substantially as shown and described.

ROBERT CAMPBELL McAlt'lllUR. Vitnesses:

WILLIAM D. FITCH, THOMAS REID. 

